U.S. Mine Safety and Health Administration spokeswoman Amy Louviere says Chamness was using a remote control to operate a toothy machine that carves coal out of the seam. She says Chamness became pinned between that equipment and the coal rib. An autopsy was planned.

The mine's operator, Knight Hawk Coal, extended its deepest sympathies to Chamness' family in a statement. The company declined additional comment, citing the ongoing investigation.

(Copyright 2013 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.)